Problem 45256. List one vertex neighbors

First input T is a triangulation connectivity indices list (triplet list of indices -positive integers-, each index refering to a vertex number in a corresponding vertices list).

Second input i is a vertex index (positive integer).

The purpose of this function is to query the list L of all i neighbor indices.

For instance if

T = [1 2 4;...
     2 3 4;...
     5 6 8;...
     6 7 8;...
     1 2 5;...
     2 5 6;...
     2 3 6;...
     3 6 7;...
     3 4 7;...
     4 7 8;...
     4 1 8;...
     1 8 5]

and i = 3, then the function should return

L = [2, 4, 6, 7]

since 2, 4, 6, and 7 are all part of triangles / rows in which 3 is also a vertex member.

Hypothesis :

- Output L doesn't need to be ordered, but must not contain duplicated index.

- Output L is a row vector , and if the vertex index is not in the list , the function must of course return the empty set, [].